I sort of think the most likely origin is that some pangolin farmer from the back end of rural Yunnan was the first host but the virus couldn't explode until someone went to bring the pangolins to market in a city with real crowds.
My experience: For decades, my father, my grandfather, and my great grandfather sold cattle via the Chicago markets. This is a trip of around 1000 km. This also originally started when our part of the US would have been no different than a very backwater part of a developing nation. No roads, no rail, no infrastructure, really, until you got to within 400-500 km of Chicago from where we live. And yet, they moved cattle that far to one single marketplace.